Murine norovirus infection in Brazilian animal facilities.

Murine norovirus (MNV) is a single-stranded positive-sense RNA virus of the Caliciviridae family. MNV has been reported to infect laboratory mice with the ability to cause lethal infections in strains lacking components of the innate immune response. Currently, MNV is considered the most prevalent infectious agent detected in laboratory mouse facilities. In this study, mice in 22 laboratory animal facilities within Brazil were analyzed for MNV infection. Using primers targeting a conserved region of the viral capsid, MNV was detected by RT-PCR in 137 of 359 mice from all 22 facilities. Nucleotide sequencing and phylogenetic analysis of the capsid region from the viral genome showed identity ranging from 87% to 99% when compared to reported MNV sequences. In addition, RAW264.7 cells inoculated with a mouse fecal suspension displayed cytopathic effect after the fifth passage. This study represents the first report of MNV in mouse colonies in Brazilian laboratory animal facilities, emphasizing the relevance of a health surveillance program in such environments.

Efeito do extrato de Curcuma longa L. sobre infecções in vitro por Staphylococcus aureus, Pseudomonas aeruginosa e Candida albicans em macrófagos murinos (RAW 264.7) / Effect of Curcuma longa L. extract on Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans in vitro infections in murine macrophages

Os seres humanos vivem em constante relação com micro-organismos, comensais e patogênicos, que podem ameaçar a homeostase do hospedeiro. Espécies patogênicas apresentam mecanismos capazes de contornar as barreiras de defesa do hospedeiro, facilitando sua disseminação e proliferação nos tecidos invadidos. Cepas resistentes aos antimicrobianos disponíveis surgem diariamente, por isso, é relevante encontrar métodos alternativos para controla-las. Produtos de plantas medicinais vem sendo investigados para essa finalidade. No presente estudo, foi avaliada a capacidade do extrato de C. longa em controlar infecções in vitro por S. aureus, P. aeruginosa e C. albicans em macrófagos murinos (RAW 264.7). Para isto, foram aplicadas as concentrações inibitórias mínimas (CIM) do extrato vegetal nas infecções e por meio de análise da fagocitose foi analisado a contribuição delas para a eliminação destes micro-organismos. A viabilidade dos macrófagos foi analisada por meio de teste colorimétrico com corante vermelho neutro. Foram checadas a produção de citocinas inflamatórias (IL-1ß, IL-6, TNF-α e IL-10) e óxido nítrico (NO), por ELISA e com reagente de Griess, respectivamente. Os resultados foram analisados por ANOVA e Tukey's Test (P ≤ 0.05). Foi verificado que o extrato de C. Longa auxiliou de maneira efetiva os macrófagos na fagocitose dos micro-organismos avaliados, apresentando reduções significativas de unidades formadoras de colônia por mililitro (UFC/mL), e atuou mediação da síntese de citocinas e NO. Os macrófagos apresentaram-se viáveis durante a infecção. Desta forma, foi constatado que o extrato de C. longa foi capaz de auxiliar in vitro os macrófagos na eliminação de S. aureus, P. aeruginosa e C. albicans, além de proporcionar efeito imunomodulador na síntese de IL-1ß, TNF-α, IL-10 e NO, no intuito de controlar as infecções microbianas in vitro(AU)

Humans live in constant contact with microorganisms, commensals and pathogens, which may threaten host homeostasis. Pathogenic species present mechanisms able circumventing the host defense barriers, facilitating their dissemination and proliferation in invaded tissues. Antimicrobial-resistant strains emerge daily, then it is important finding an alternative method to control them. Medicinal plant products have been investigated for this purpose. In this study, the ability of C. longa extract to control in vitro infections by S. aureus, P. aeruginosa and C. albicans in murine macrophages (RAW 264.7) was evaluated. For this, the minimum inhibitory concentrations (MIC) of the plant extract were used in the infections. Phagocytosis was analyzed to check if they would contribute to eliminate these microorganisms. The viability of the macrophages was analyzed by colorimetric test using neutral red dye. Productions of inflammatory cytokines (IL-1ß, IL-6, TNF-α and IL-10) and nitric oxide (NO) were verified during infection by ELISA and Griess's reagent, respectively. The results were analyzed by ANOVA and Tukey's Test (P ≤ 0.05). C. Longa L. extract effectively assisted the macrophages in the phagocytosis of the evaluated microorganisms, presenting significant reductions of colony-forming units per milliliter (CFU/mL), and mediated the synthesis of cytokines and NO. In addition, macrophages were viable during infection. C. Longa L. extract assisted in vitro the macrophages in the elimination of S. aureus, P. aeruginosa, and C. albicans, promoting immunomodulatory effect in the synthesis of IL-1ß, TNF-α, IL-10 and NO, in order to control microbial infections in vitro(AU)